Re: [PATCH 4/7 v2] tracing: Have trace events system open call tracing_open_generic_tr()

[Steven Rostedt]

On Fri, 11 Oct 2019 20:57:51 -0400
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

> --- a/kernel/trace/trace_events.c
> +++ b/kernel/trace/trace_events.c
> @@ -1391,9 +1391,6 @@ static int subsystem_open(struct inode *inode, struct file *filp)
>  	struct trace_array *tr;
>  	int ret;
>  
> -	if (tracing_is_disabled())
> -		return -ENODEV;
> -
>  	/* Make sure the system still exists */
>  	mutex_lock(&event_mutex);
>  	mutex_lock(&trace_types_lock);
> @@ -1420,16 +1417,9 @@ static int subsystem_open(struct inode *inode, struct file *filp)
>  	WARN_ON(!dir);
>  
>  	/* Still need to increment the ref count of the system */
> -	if (trace_array_get(tr) < 0) {
> -		put_system(dir);
> -		return -ENODEV;
> -	}
> -
> -	ret = tracing_open_generic(inode, filp);
> -	if (ret < 0) {
> -		trace_array_put(tr);
> +	ret = tracing_open_generic_tr(inode, filp);
> +	if (ret < 0)
>  		put_system(dir);
> -	}
>  
>  	return ret;
>  }

I got a bit too aggressive on this patch. The subsystem_open() gets the
tr from a search, not from the inode. Thus it can't use the
tracing_open_generic_tr() call. It needs to do the trace_array_get()
directly.

V2 of this patch:

-- Steve